package com.luchao.blockchain.security;

import java.security.MessageDigest;

/**
 * 加密工具类
 * @author ZhaoLu
 *
 */
public class CryptoUtil {
	
	/**
	 * 利用java原生的摘要实现SHA256加密
	 * @param str
	 * @return
	 */
	public static String SAH256(String str) {
		MessageDigest messageDigest;
		String encodeStr = "";
		try {
			messageDigest = MessageDigest.getInstance("SHA-256");
			messageDigest.update(str.getBytes("UTF-8"));
			encodeStr = byte2Hex(messageDigest.digest());
		} catch (Exception e) {
			System.out.println("getSHA256 is error"+e.getMessage());
		}
		return encodeStr;
	}
	
	 /**
     * 将byte转为16进制
     * @param bytes
     * @return
     */
    private static String byte2Hex(byte[] bytes){
        StringBuffer stringBuffer = new StringBuffer();
        String temp = null;
        for (int i=0;i<bytes.length;i++){
            temp = Integer.toHexString(bytes[i] & 0xFF);
            if (temp.length()==1){
                //1得到一位的进行补0操作
                stringBuffer.append("0");
            }
            stringBuffer.append(temp);
        }
        return stringBuffer.toString();
    }

}
